/Engine/Source/Runtime/Core/Public/String/Join.h
Append every element of the range to the builder, separating the elements by the delimiter.
The builder, to allow additional operations to be composed with this one.
namespace UE { namespace String { template<typename RangeType, typename ProjectionType, typename DelimiterType, typename CharType> [TStringBuilderBase](API\Runtime\Core\Containers\TStringBuilderBase)< CharType > & UE::String::JoinByTo ( RangeType && Range, ProjectionType Projection, DelimiterType && Delimiter, [TStringBuilderBase](API\Runtime\Core\Containers\TStringBuilderBase)< CharType > & Builder ) } }